2. Line your eyes with black gel liner. Dip an eyeliner brush into a black gel liner, like Rimmel London's Scandal Eyes Waterproof Gel Liner, and run it along your top lashline, increasing the thickness of the line as you inch toward the outer corner of your eye.

3. Intensify your cat-eye at the outer corners. Use the same gel liner and a flat-tip eyeshadow brush to add product to your lower lashline from the center toward the outer corner of your eye. "Make sure the upper and lower line meets at the outer corner of your eye to ensure the liner looks seamless," Cosenza says.